Varied inspection equipment is conventionally known for detecting electrical defects in minute electronic circuits formed on a semiconductor chip. Such inspection equipment includes EB tester (Electron Beam tester) and prober device. The EB tester is a device for detecting points of electrical defect in LSIs. This detection is carried out by irradiating a point of measurement with an electron beam utilizing the following phenomenon: the amount of secondary electron emission from the point of measurement when irradiated with an electron beam varies depending on the value of voltage of the point of measurement. The prober device is a device for measuring the electrical characteristics of LSIs. This measurement is carried out by bringing a plurality of mechanical probes, disposed in correspondence with the positions of pads for characteristics measurement on LSIs, into contact with the measuring pads. In such an EB tester or prober device, the equipment operator manually confirms the probing positions of probes while viewing images, such as optical microscope images and SEM (Scanning Electron Microscope) images of wiring.
Recently, circuit patterns formed on semiconductor devices, such as LSIs, have been increasingly microminiaturized and complicated. It is becoming difficult to move probes to optimum probing positions in a short time. To cope with this, techniques designated as CAD navigation have been developed for shortening the time required for probing. The CAD navigation is such that the wiring layout of a semiconductor device is displayed in alignment with the actual image of the semiconductor device viewed by the equipment operator during probing. For example, Patent Document 1 discloses an example of an EB tester using CAD navigation. Patent Document 2 discloses an example in which CAD navigation is applied to FIB (Focused Ion Beam) processing equipment. In the technique disclosed in Patent Document 2, a secondary electron image produced by a test piece to be processed when the test piece is irradiated with a focused ion beam is observed. In this way, an appropriate position of ion beam irradiation is determined.
The techniques disclosed in Patent Documents 1 and 2 are those for carrying out defect inspection on semiconductor chips. There is also demand for carrying out defect inspection on wiring patterns on semiconductor wafers before they are formed into chips. Patent Document 3 discloses a technique for moving probes to positions of FIB processing so as to move a processed piece, obtained by FIB processing, from a predetermined position in the wiring pattern on a wafer by the probes. More specifically, FIB processing equipment is provided with a probe information screen for displaying the image of the tip of a probe. The equipment user specifies a target location to which the probe is to be moved on the probe information screen. The equipment computes the difference between the inputted target location and the present position of the tip of the probe, and moves the probe to the target location. Thus, when the probe is moved to a target location on a wafer, a burden on the equipment user can be lessened.
[Patent Document 1] Japanese Patent Laid-Open No. H7(1995)-240446
[Patent Document 2] Japanese Patent Laid-Open No. H8(1996)-54447
[Patent Document 3] Japanese Patent Laid-Open No. 2000-147070